1. Field of the Invention
The present invention relates to a reflector movable type headlamp in which a reflector mounted with a light source is inclinably supported relative to a lamp body by an aiming mechanism. In particular, the present invention relates to a reflector movable type headlamp for an automobile or other vehicle having a structure in which a nut member, constituting an aiming point constituent member, screwed to an aiming screw, constituting an aiming mechanism constituent member, is supported by a nut sliding guide formed at a lamp body.
2. Description of the Related Art
As shown by FIG. 19, according to a conventional headlamp for an automobile, a reflector 2, integrally mounted with a light source, is supported by an aiming mechanism. The aiming mechanism is constituted by one piece of a ball and socket joint constituting an inclinable or aiming fulcrum, and two pieces of nut members constituting movable fulcrums respectively screwed to two pieces of aiming screws and extractable and retractable in the axial direction, on a front face side of a lamp body 1 made of synthetic resin.
More specifically, the aiming screw 4 is rotatably supported by a screw insertion hole 1a provided at the lamp body 1 and a screw portion 4a of the aiming screw 4 extended to a front side of the lamp body 1, and screwed with the nut member 5 attached to a bracket 2a formed to extend from the reflector 2. By pivoting the aiming screw 4, the nut member 5 is extracted and retracted along the aiming screw and the reflector 2 is inclined around an inclining axis connecting the ball and socket joint and the nut member screwed to the other aiming screw. Thereby, an optical axis of the lamp can be adjusted.
The aiming screw 4 is made of metal and integrally formed with a crowned gear 7 at its rear end portion and can be operated to pivot by using a driver D. Further, the aiming screw 4 inserted into the screw insertion hole 1a from a rear side of the lamp body 1, is fixedly positioned by being elastically supported in a front and rear direction by a push-on fix 8 made of metal.
Further, an O-ring 9 constituting a seal member is interposed in the screw insertion hole 1a rotatably supporting the aiming screw 4 to thereby waterproof a rotational support portion of the aiming screw 4.
However, according to the headlamp having the aiming mechanism having this kind of structure, a front end portion of the aiming screw 4, supported by the screw insertion hole 1a in a cantilever style, is operated with the weight W of the reflector 2. As such, there is concern that the aiming screw 4 is fluctuated relative to the screw insertion hole 1a to thereby vibrate the reflector 2. Hence, the aiming screw 4 is held by being strongly brought into press contact with a peripheral edge portion of the screw insertion hole 1a by a push-on fix 8 to thereby prevent fluctuation of the aiming screw 4 (vibration of the reflector 2).
However, when a force used with the push-on fix 8 for pinching the aiming screw 4 is increased, there poses a problem that pivotal movability of the aiming screw 4 is deteriorated and aiming becomes difficult.
Hence, the applicant has proposed Japanese Patent Application Number 2000-165437 (filed on Jun. 2, 2000). According thereto, as shown by FIG. 20, a nut member is constituted by a structure in which sides of a nut member main body 5 formed with a female screw portion screwed with an aiming screw 4, are integrally formed with an engaging projection 6 constituting a mounting portion of a bracket 2a on a side of a reflector 2, and a slider portion 7 constituting a portion slidingly engaged with a sliding guide 8 provided at a lamp body 1 in parallel with the aiming screw 4 to be orthogonal to each other in front view. As such, the slider portion 7 is supported and carried by the sliding guide 8 to thereby alleviate weight load on the side of the reflector 2 operated to the aiming screw 4 and restrain fluctuation (vibration) of the reflector 2. Notation 9 designates a front face lens, notation xe2x80x9caxe2x80x9d designates an aiming fulcrum, notation Lx designates a horizontal inclining axis and notation Ly designates a vertical inclining axis.
According to the above-described reference (Japanese Patent Application No. 2000-165437), since the weight load on the side of the reflector 2 is carried by the sliding guide 8 and therefore, the weight load on the side of the reflector 2 is not operated to the aiming screw 4 as bending movement. However, by inertia weight on the side of the reflector operated to the engaging projection 6 provided to offset to the side of the nut member main body 5 screwed with the aiming screw 4, torsional movement is produced at the nut member and it is difficult to firmly restrain vibration of the reflector. Further, as shown by a white arrow mark, when the torsional moment is repeatedly operated to the nut member, there also poses a problem that there is also a concern that the nut member is pivoted freely relative to the aiming screw and proper aiming cannot be carried out.
Further, there also poses a problem that the nut member is formed by a T-like shape or an L-like shape in front view and therefore, bulky and the lamp body is large-sized.
The present invention has been carried out in view of the problems of the conventional technologies and it is an object thereof to provide a compact reflector movable type headlamp for an automobile capable of firmly preventing vibration of a reflector and capable of ensuring smooth pivotal movement of an aiming screw.
In order to achieve the above-described object, according to a first aspect of the invention, there is provided a reflector movable type headlamp comprising a lamp body, a front face lens integrated with a front face opening portion of the lamp body to form a lamp chamber, a light source, a reflector contained in the lamp chamber and positioned to reflect light originating from the light source, and an aiming mechanism interposed between the lamp body and the reflector and operable to inclinably support and move the reflector relative to the lamp body. The
aiming mechanism includes:
a screw insertion hole;
an aiming fulcrum constituting an inclining fulcrum of the reflector;
an aiming screw rotatably supported by the screw insertion hole and operable to move the reflector by pivotal movement of the aiming screw;
a bracket extendedly formed at the reflector;
a nut member mounted to the bracket and constituting an aiming point constituent member, the nut member screwed to the aiming screw and operable to be extracted and retracted in a front and rear direction in cooperation with the pivotal movement of the aiming screw; and
a nut sliding guide integrally and extendedly formed with the lamp body for carrying and slidably supporting the nut member in the front and rear direction;
wherein a mounting portion of the nut member and the bracket constituting an aiming point, is provided with stress relieving means having a ball and socket joint structure for relieving stress produced at the mounting portion in accordance with extracting and retracting the nut member;
wherein the nut sliding guide is provided at a position offset to a side position of a position of arranging the aiming screw on a side opposed to the aiming fulcrum;
wherein the nut member constitutes a ball portion of the ball and socket structure by a nut member main body screwed to the aiming screw and is integrally formed with a slider portion supported by the nut sliding guide at a side position of the nut member main body; and
wherein a side of the bracket is provided with an engaging hole opened to a side of the nut sliding guide, supporting the nut member main body and constituting a ball receive portion of the ball and socket joint.
In operation, the nut sliding guide integrally formed with the lamp body carries the weight for the reflector operated to the nut member screwed to the aiming screw. Accordingly, the aiming screw is not operated with bending moment by the weight of the reflector. Therefore, pivotal movement of the aiming screw relative to the screw insertion hole and accordingly, vibration of the reflector is restrained and therefore, smooth pivotal movement of the aiming screw can be ensured by weakening pinching force at a rotational support portion of the aiming screw by a push-on fix or the like more than that in the conventional constitution.
Further, a point of operating the weight of the side of the reflector to the nut member coincides with a screwed portion of the nut member and the aiming screw and therefore, torsional moment caused by the weight on the side of the reflector is not operated to the nut member. Therefore, there is not a concern of vibrating the reflector or freely pivoting the nut member relative to the aiming screw.
Further, stress which is going to be produced at the mounting portion of the nut member and the bracket (between the aiming screw and the reflector) when the reflector is inclined relative to the lamp body in accordance with extraction or retraction of the nut member, or when the reflector is thermally expanded due to heat generation of the light source, is relieved by the stress relieving means of the ball and socket joint structure provided at the mounting portion of the nut member and the bracket.
Also, the nut member extracted and retracted in the front and rear direction in accordance with pivotal movement of the aiming screw, is guided in a direction along the aiming screw by the nut sliding guide and therefore, frictional torque of the screwed portion of the nut member and the aiming screw is maintained constant.
Further, interference between the inclining reflector and the nut sliding guide can be avoided by arranging the nut sliding guide at a position of a wide space between the lamp body and the reflector which is the position offset to a side of arranging the aiming screw.
In addition, the nut member is constructed by a compact structure integrally formed with the slider portion at a side of the nut member main body and therefore, the nut member can be arranged in a narrow space between the lamp body and the reflector.
According to a second aspect of the present invention, a peripheral area of the engaging hole of the bracket, constituting the ball receive portion of the ball and socket joint is formed, in a section thereof, in a U-like shape which does not interfere with the aiming screw screwed to a female screw portion of the nut member main body supported by the engaging hole and extended in the front and rear direction.
In operation, the bracket and the aiming screw do not interfere with each other by penetrating the aiming screw screwed to the nut member main body engaged with the engaging hole and extended in the front and rear direction, into an opening portion (slit) forward and rearward from a peripheral area of the engaging hole.
According to a third aspect of the present invention, the nut member main body and the engaging hole are constituted to be slidable to each other in a front and rear direction of a direction of an opening of the engaging hole, pivotable to each other along a plane including the aiming fulcrum and the aiming screw, and pivotable relative to each other in a peripheral direction of the engaging hole to thereby constitute the stress relieving means of the ball and socket structure.
In operation, as an example, as shown by FIG. 17, in accordance with pivotal movement of an aiming screw 30, a nut member 130 is extracted and retracted in a front and rear direction (linear movement) along the screw 30 as shown by an arrow mark A. Meanwhile, as shown by an arrow mark B, an engaging hole 152 of a bracket 150a of a reflector 14 is rotated (inclined) around an aiming fulcrum P (vertical inclining axis Ly). Therefore, at an engaging portion (nut member main body 131 and engaging hole 152) between two members (nut member 130 executing linear movement and bracket 150a executing rotational movement) having different movement loci, there is produced stress in correspondence with a difference (deviation) of the movement loci.
However, in accordance with extracting and retracting operation in the front and rear direction along the screw 30 of the nut member 130, the nut member main body 131 and the engaging hole 152 on a side of the bracket 150a are slid relative to each other in an engaging direction(direction of extending engaging hole 152) and relieve tensile stress (compressive stress) at a mounting portion between the nut member 130 and the bracket 150a in correspondence with a deviation in a direction along a horizontal inclining axis Lx passing through the aiming fulcrum P.
Also, the nut member main body 131 and the engaging hole 152 are pivoted relative to each other in the horizontal direction (relative pivotal movement around an axis L10 of FIGS. 9, 10) to thereby relieve torque in correspondence with angular deviation between a direction L2 of extending the engaging hole 152 and a direction L3 of projecting the nut member main body 131 at the mounting portion between the nut member 130 and the bracket 150a. That is, there is relieved stress produced at the mounting portion when the reflector 14 is inclined around the vertical inclining axis Ly passing through the aiming fulcrum P.
In addition, there is relieved stress produced at the mounting portion between the nut member 130 and the bracket 150a when the nut member main body 131 and the engaging hole 152 are pivoted relative to each other in the peripheral direction of the engaging hole 152 and the reflector 14 is inclined around the horizontal inclining axis Lx passing through the aiming fulcrum P.
Also, when the reflector 14 is thermally expanded by cause of heat generation of the light source, there is going to be produced stress accompanied by deformation of the reflector 14 at the mounting portion between the nut member 130 and the bracket 150a. This stress is relieved by a universal joint structure constituted by the nut member main body 131 and the engaging hole 152.
According to a fourth aspect of the present invention, the nut member main body according to the third aspect of the invention is formed in a spherical shape matching with an inner peripheral face of the engaging hole formed in a cylindrical shape and is provided with a pair of elastic projections brought into press contact with the inner peripheral face of the engaging hole for constituting a relative pivotal movement axis between the nut main body and the engaging hole at opposed positions in an outer periphery of the nut member main body interposing the female screw portion.
In operation, the pair of elastic projections on the side of the nut member main body are brought into press contact with and held by the inner peripheral face of the engaging hole and the nut member and the engaging hole can be slid relative to each other around an axis connecting the pair of elastic projections.
According to a fifth aspect of the present invention, the elastic projection according to the fourth aspect of the invention includes an elastic engaging frame in a shape of a gate extended in a direction of crossing the female screw portion and a spherical very small projection projected from a horizontal beam portion of the elastic engaging frame and an inner peripheral face of the engaging hole is opposedly provided with a pair of engaging grooves extended along a direction of extending the engaging hole, brought into press contact with the elastic engaging frame in a radius direction of the engaging hole, and loosely fitted in a peripheral direction of the engaging hole.
In operation, the horizontal beam portion of the elastic engaging frame in the gate shape is brought into contact with the bottom face of the engaging groove of the engaging hole. As such, there is no play between the nut member main body and the engaging hole, and the nut member main body and the engaging hole can be slid relative to each other in the direction of extending the engaging hole. The elastic engaging frame in the gate shape loosely fitted to the engaging groove in the groove width direction, can be pivoted relative to the nut member main body in the peripheral direction of the engaging hole by an amount in correspondence with a gap between the engaging groove and elastic engaging frame. Press-contact force is the largest at the very small projection position of the horizontal beam portion of the elastic engaging frame in the gate shape brought into press contact with the bottom face of the engaging groove. Therefore, the nut member main body and the engaging hole are pivoted relative to each other around the axis passing through the pair of very small projections.
Particularly, by forming the bottom face of the engaging groove in a shape following that of the inner peripheral face of the engaging hole and forming an outer side surface of the horizontal beam portion of the elastic engaging frame in the gate shape by a shape of a circular arc in its cross-section, pivoting of the nut member main body and the engaging hole relative to each other in the peripheral direction of the engaging hole can be made smooth, and a relative pivotal movement range in the peripheral direction of the engaging hole can be enlarged.
According to a sixth aspect of the present invention, the nut sliding guide may be formed with a dovetail groove having a wide width, in which a side thereof opposed to the aiming screw is opened and the slider portion includes a flat slide plate portion contained in the dovetail groove and an elastic sliding contact portion in a shape of a leaf spring brought into press contact with a bottom face of the dovetail groove for elastically supporting the slide plate portion in a depth direction of the dovetail groove.
In operation, the elastic extended portion in the shape of the leaf spring is brought into press contact with the bottom face of the dovetail groove (nut sliding guide), the slide plate portion is elastically supported in the dovetail groove (nut sliding guide) without play and smooth sliding movement along the nut sliding guide (aiming screw) of the nut member is ensured.
According to seventh aspect of the present invention, the aiming screw comprises an upper and lower aiming screw arranged at a position of being separated from the aiming fulcrum in an upper and lower direction and a left and right aiming screw arranged at a position of being separated from the aiming fulcrum in a left and right direction.
In operation, by pivotal movement of the upper and lower aiming screw, the nut member is extracted and retracted along the upper and lower aiming screw and the reflector is inclined around the horizontal inclining axis passing through the aiming fulcrum and the mounting portion between the nut member and the bracket screwed to the left and right aiming screw (left and right aiming point).
By pivotal movement of the left and right aiming screw, the nut member is extracted and retracted along the left and right aiming screw and the reflector is inclined around the vertical inclining axis passing through the aiming fulcrum and the mounting portion between the nut member and the bracket screwed to the upper and lower aiming screw (upper and lower aiming point).
The nut sliding guide in correspondence with the left and right aiming point mainly carries the weight of the reflector and restrains vibration in the upper and lower direction of the reflector. Further, the nut sliding guide in correspondence with the upper and lower aiming point restrains vibration in the left and right direction of the reflector.
According to an eighth aspect of the present invention, the reflector and the aiming screw may be made of synthetic resin, and the aiming fulcrum is constituted by a ball and socket joint comprising a ball portion made of synthetic resin projected to either one of a side of the reflector and a side of the lamp body and a ball receive portion made of synthetic resin engageable with the ball portion.
By constituting the reflector and the aiming screw and the ball and socket joint comprising the ball portion and the ball receive portion constituting the aiming fulcrum by synthetic resin, the entire aiming mechanism can be constituted by synthetic resin.
Further, the screw insertion hole may be constituted by a cylindrical portion integrally formed with the lamp body and extended in the front direction by penetrating the lamp body. On a front end side of a supported portion of the aiming screw supported by the screw insertion hole, there is integrally formed an elastic locking portion capable of passing through the screw insertion hole by being elastically deformed to an inner side in a radius direction and engaged with a peripheral edge portion on a front end side of the screw insertion hole to thereby prevent the aiming screw from drawing in a rear direction. Meanwhile, on a rear end side of the supported portion, there is integrally formed an elastic rib in a skirt-like shape brought into press contact with a peripheral edge portion on a rear end side of the screw insertion hole to thereby fixedly position the aiming screw in the front and rear direction.
In addition, by constituting the present invention in this way, when the aiming screw is pushed into the screw insertion hole from a rear side of the lamp body, the elastic locking portion of the supported portion in the aiming screw passes through the cylindrical portion by being elastically deformed to contract to the inner side in the radius direction by being pushed by the peripheral edge portion of the rear end side of the screw insertion hole and then engages with the peripheral edge portion on the front end side. Further, the skirt-like elastic rib is brought into press contact with the peripheral edge portion on the rear end side of the screw insertion hole to thereby fixedly position the aiming screw in the axial direction relative to the screw insertion hole.
Also, the elastic rib in the skirt-like shape formed on the rear end side of the supported portion of the aiming screw, and brought into press contact and sliding contact with the peripheral edge portion of the screw insertion hole, more or less prevents water from invading inside of the supported portion of the aiming screw and elastically supports the aiming screw in the front and rear direction.
In addition, either of the elastic rib and the lamp body is made of synthetic resin. Therefore, sliding movement of the both members is ensured at the sliding contact portion between the elastic rib and the peripheral edge portion of the screw insertion hole and pivotal movement of the aiming screw is not hampered. Further, the elastic rib made of synthetic resin is less deteriorated by water than an O-ring made of rubber.
As a result, by the elastic rib in the skirt-like shape formed integrally with the aiming screw and brought into press contact and sliding contact with the peripheral edge portion of the screw insertion hole, the aiming screw is elastically supported without play in the front and rear direction at the rotational support portion, and waterproofing at the rotational support portion of the aiming screw is ensured to some degree and therefore, it is not necessary to interpose an elastic member such as a push-on fix or the like or a seal member such as an O-ring at the rotational support portion of the aiming screw. Accordingly, the number of parts constituting the aiming mechanism is reduced, the constitution of the aiming mechanism is simplified and operation of integrating the aiming mechanism is also simplified.
Further, the elastic rib made of synthetic resin is not deteriorated by water after a long period of use and elastic support over a long period of time and waterproofing, to some degree, are guaranteed at the rotational support portion of the aiming screw.
Also, there may be constructed a constitution in which the supported portion of the aiming screw is integrally formed with an elastic waterproof rib in a ring-like shape brought into sliding contact with the inner peripheral face of the screw insertion hole.
By constituting the present invention in this way, the elastic waterproof rib in the ring-like shape formed at the supported portion of the aiming screw and brought into sliding contact with the inner peripheral face of the screw insertion hole, is held in a press-contact state at the inner peripheral face of the screw insertion hole and ensures waterproof at the rotational support portion of the aiming screw.
Since the waterproof rib made of synthetic resin is provided with elasticity (flexibility), when the supported portion of the aiming screw is inserted into the cylindrical portion (screw insertion hole), the elastic waterproof rib is elastically deformed and does not hamper integration of the aiming screw to the screw insertion hole. Further, a sliding contact portion between the elastic waterproof rib and the inner peripheral face of the screw insertion hole, does not hamper pivotal movement of the aiming screw.
The elastic waterproof rib made of synthetic resin is also less deteriorated by water than an O-ring made of rubber.
As a result, the rotational support portion of the aiming screw is waterproofed at two locations of waterproofing means by the elastic rib at the peripheral edge portion of the screw insertion hole on an outer side of the lamp body, and waterproofing means by the elastic waterproof rib at inside of the screw insertion hole and therefore, the rotational support portion of the aiming screw can be waterproofed.